Authentication

The Jules REST API uses API keys for authentication. You’ll need a valid API key to make API requests.

Getting Your API Key

1. Go to jules.google.com/settings
2. Find the API Key section
3. Click Generate API Key (or copy your existing key)
4. Store the key securely — it won’t be shown again

Keep your API key secret. Don’t commit it to version control or share it publicly.

Using Your API Key

Include the API key in the x-goog-api-key header with every request:

curl -H "x-goog-api-key: YOUR_API_KEY" \
  https://jules.googleapis.com/v1alpha/sessions

Environment Variable (Recommended)

Store your API key in an environment variable:

export JULES_API_KEY="your-api-key-here"

Then use it in requests:

curl -H "x-goog-api-key: $JULES_API_KEY" \
  https://jules.googleapis.com/v1alpha/sessions

Example: Create a Session

curl -X POST \
  -H "x-goog-api-key: $JULES_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Add unit tests for the utils module",
    "sourceContext": {
      "source": "sources/github-owner-repo",
      "githubRepoContext": {
        "startingBranch": "main"
      }
    }
  }' \
  https://jules.googleapis.com/v1alpha/sessions

Example: List Sessions

curl -H "x-goog-api-key: $JULES_API_KEY" \
  https://jules.googleapis.com/v1alpha/sessions

Troubleshooting

”API key not valid”

• Verify you copied the entire key without extra spaces
• Check that the key hasn’t been revoked in settings
• Generate a new key if needed

”Permission denied”

• Verify your account has access to Jules
• Check that you have access to the requested resources (sessions, sources)

“Quota exceeded”

• You may have hit rate limits